Twin towns or sister cities are a form of legal and social agreement between towns, cities, counties, oblasts, prefectures, provinces, regions, states, and even countries in geographically and politically distinct areas to promote cultural and commercial ties. The modern concept of town twinning, conceived after the Second World War in 1947, was intended to foster friendship and understanding between different cultures and between former foes as an act of peace and reconciliation, and to encourage trade and tourism. In recent times, town twinning has increasingly been used to form strategic international business links between member cities.
In the United Kingdom, the term "twin towns" is used; in the Americas, the term "sister cities" is generally used. In mainland Europe, the most commonly used terms are "twin towns", "partnership towns", "partner towns" and "friendship towns". The European Commission uses the term "twinned towns" and refers to the process as "town twinning". Germany, Poland and the Czech Republic use Partnerstadt, Miasto Partnerskie and Partnerské město respectively, which translate as "Partner Town or City". France uses Ville jumelée (twinned town) and Italy has Gemellaggio (twinning) and Comune gemellato (twinned municipality). In the Netherlands, the term is Stedenband (Cities-bond). In Greece, the word αδελφοποίηση (adelfopiisi—fraternisation) has been adopted. In Iceland, the terms vinabæir (friend towns) and vinaborgir (friend cities) are used. In the former Soviet bloc, "twin towns" and "twin cities" are used, along with города-побратимы (sworn brother cities).
Sister Cities is an upcoming indie-drama film directed by Sean Hanish based on the internationally-acclaimed 2006 play of the same name by Colette Freedman. The film stars Stana Katic, Jess Weixler, Michelle Trachtenberg, and Troian Bellisario as the four sisters along with Jacki Weaver, Alfred Molina, Amy Smart, and Tom Everett Scott filling out the rest of the cast.
Four estranged sisters - as different as the cities they were named after - reunite to mourn what they believe is the suicide of their mother.
On July 16, 2015, Kaia Gerber was cast as a young Carolina. On July 20, 2015, it was confirmed that Troian Bellisario, Stana Katic, Jess Weixler, and Michelle Trachtenberg had signed on to play the four sisters, Baltimore, Carolina, Austin, and Dallas, respectively. The following day, it was confirmed Jacki Weaver and Amy Smart was cast as a Mary and young Mary, respectively along with Alfred Molina.Aimee Garcia joined the cast as Sarah, a girlfriend of one of the sisters.